With the prevalence of credit cards and other types of non-cash payment mechanisms in modern commerce, traditional manners of tipping (paying a gratuity to) a waiter in a restaurant or other full-service retail establishment can be inefficient and time-consuming. Before a customer, who may be in a hurry to leave for the next destination, writes down the tip amount on a credit card receipt, he or she needs to calculate a tip amount, which can be based on various factors such as the type of service or product rendered, the total amount of sale, the local custom specific to that geographical region and/or that industry, the quality of service, and so forth. Many consumers find this process difficult or annoying.